Flask



FIG. 1 is a front perspective view of a first embodiment of a flask showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof;

FIG. 7 is a right side view thereof;

FIG. 8 is a front perspective view of a second embodiment of a flask showing our new design;

FIG. 9 is a front view thereof;

FIG. 10 is a back view thereof;

FIG. 11 is a left side view thereof;

FIG. 12 is a top view thereof;

FIG. 13 is a bottom view thereof; and,

FIG. 14 is a right side view thereof.

The dash-dot-dash broken line of FIG. 13 represents a boundary of the claimed design. All other broken lines illustrate portions of the flask that form no part of the claimed design. 

CLAIM The ornamental design for a flask, as shown and described. 